A digital video signal may be transmitted from a video server to a video receiver. For example, a digital video signal might be transmitted from a video server associated with a cable television company to a set-top box associated with a television. The set-top box may process the received video signal and arrange for a moving image to be displayed on the television.
In some cases, however, an original digital video signal may be altered or tampered with using video editing software and/or hardware before the signal reaches the video receiver. By way of example, images or portions of images could be deleted from (or inserted into) a news or sports video image. Moreover, such changes could be difficult or impossible for a viewer to detect.